• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.5
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• pp.975-982
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• 2006

To cope with the recent developments of info-communication technology and information infrastructure, and in particular, to respond to the environment of wire and wireless communication integration, and also to overcome the limit of the existing web-based Port-MIS, the Ministry of Maritime Affairs and Fisheries is developing a mobile Port-MIS public service system (hereinafter referred to as a mobile Port-MIS). Accordingly, this study analyzes the current situation of the mobile Port-MIS that is under operation of the lust stage, finding out the problems, and suggesting new measures to activate the mobile Port-MIS. We expect this study will be able to suggest a guideline to the government institutions or other related organizations that plan to introduce a mobile technology in the near future.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.67-70
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• 2005

As the demand of sea leisure increases recently, interest is converged sea safety and offer of quick and systematic information according to weather environment that change rapidly. Use of Electronic Navigational Chart(ENC) in the sea in offer of geography information through Mobile terminal was gone to level that run in PDA environment in domestic by bulky good physician data information and complicated processing way of island in the sea expression in sea, and is loaded in obligatory sailing equipment of ship yet and is used. In this paper, we develop server system that take charge index for offer of quick information through Restrictive resource management and Caching Technique, image conversion and database construction and fast search to service various marine leisure informations of Weather Data and so on and image information of ENC in the sea to Mobile portable phone terminal efficiently.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2423-2428
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• 2015

We have implemented a personal prescription management system which enables resource-limited mobile device to utilize the optical character recognition technique. The system enables us to automatically detect and recognize the text in the personal prescription by using a optical character recognition technique. We improved the recognition rate over a pre-processing in order to improve the character recognition rate of the original method. The examples such as a personal prescription management service, alarm service, and drug information service with mobile devices have been demonstrated by using the our system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.100-101
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• 2012

According to growing the leisure boat market, safety-related and weather information have been required by different users with different electronic devices. NAVTEX messages transmitting worldwide from local stations are a kind of useful service, even for non mandatory carriage requirement vessel, such as small or fishing vessels. However, it is not easy for all users to recognize intuitively. This paper is to implement the NAVTEX message on tablet PC, indicating warning positions of message on Android-based google map.

• Journal of Communications and Networks
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• v.14 no.6
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• pp.692-702
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• 2012

Supporting quality of service (QoS) guarantees for diverse multimedia services are the primary concerns for WiMAX (IEEE 802.16) networks. A scheduling scheme that satisfies QoS requirements has become more important for wireless communications. We propose a downlink scheduling scheme called adaptive priority-based downlink scheduling (APDS) for providing QoS guarantees in IEEE 802.16 networks. APDS comprises two major components: Priority assignment and resource allocation. Different service-type connections primarily depend on their QoS requirements to adjust priority assignments and dispatch bandwidth resources dynamically. We consider both starvation avoidance and resource management. Simulation results show that our APDS methodology outperforms the representative scheduling approaches in QoS satisfaction and maintains fairness in starvation prevention.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.406-407
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• 2022

자율운항선박, 무인선과 같이 전통적 선박 형태에 자율성이 부여되는 형태로의 발전과 함께 드론, 비행체 같은 비행 형태까지 포함하는 해상 모빌리티는 기존 통신 체계 대비 실시간성 향상 및 대용량 데이터 교환이 요구되는 새로운 해상 안전 운항 체계가 수반되어야 한다. 초고속해상무선통신망(LTE-Maritime) 송수신기를 장착한 국내 선박의 경우, LTE급의 통신 서비스를 연안 최대 100km까지 받을 수 있지만, 국제 항해를 하는 국적선과 외국적 선박을 포함하는 해상 모빌리티 안전 운항 체계 구축을 위해서는 VDES(VHF Data Exchange System)와 같은 국제협약에서 인정하고 해상이동서비스(Maritime Mobile Service)에 속하면서 기존보다 빠른 통신망의 보급이 필수적이다. 본 논문에서는 향후 해상 모빌리티 구현을 위해 필요한 해상무선통신망의 하나로 VDES의 필요성에 주목하여 그간의 개발 현황으로부터 향후 VDES 서비스 도입 및 활용방안에 관해 논한다.

• Journal of Positioning, Navigation, and Timing
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• v.7 no.4
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• pp.217-226
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• 2018

According to the Korea Coast Guard's maritime disaster statistics (Korea Coast Guard 2017, Korean Statistical information Service 2018), an average of 2,140 marine accidents occurred every year for the past 6 years and the number of accidents is increasing every year. Among them, maritime accidents of fishing vessels are the most frequent, and recently accidents involving fishing boat and leisure vessels are rapidly increasing as well. In particular, the number of accidents involving leisure vessels increased to about one-third of the accidents of fishing vessels, and emergency rescue requests are increasing every year accordingly. However, the number of crash accidents involving users of small vessels and marine leisure activities are increasing because of the difficulties of installing navigation equipment and electronic navigation charts. Recently, the demand for precise positioning using mobile devices is increasing in the fields of maritime safety, piloting support, and coastal survey. Although various applications of smart devices provide location-based services for users, the measurement results are discontinuous when using the position coordinates of the National Marine Electronics Association (NMEA) calculated by smartphone. Recently, Google announced that they will provide GPS raw data to developers from Android 7.0 Nougat. As a result, developers have an opportunity to receive precise carrier phase and code measurements to make more accurate positioning according to the performance of Android devices. This study analyzed GPS positioning performance using Android devices, and compared and analyzed the positioning performance at sea with high-performance GPS receivers.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.2
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• pp.217-225
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• 2024

Even after the introduction of Global Maritime Distress and Safety System (GMDSS), many maritime accidents occur. A method of transmitting a rescue signal when a person falls into the water from a ship is currently being researched and developed in various ways, but no products have been developed that use frequencies allocated for maritime mobile service. Accordingly, in this study, we designed and produced a man-over-board (MOB) device by applying Group B AMRD technologies, which were adopted through the latest revision of the International Telecommunication Union (ITU). In addition, a receiver and user interface were built to verify the performance of the transmitter, and we confirmed that it can be used in conjunction with existing electronic charts. This MOB device satisfies the general and technical requirements of Group B AMRD using AIS technology and uses integrated components for miniaturization for easy portability in a maritime environment. We expect that it will achieve excellent AIS communication and be essential in rapid response and safety in emergency scenarios.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.9
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• pp.774-781
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• 2014

Demand for spectrum resources is increasing with the development of mobile telecommunications and so is their economic value. As a way to enhance the economic efficiency of use of spectrum resources, many countries have focused on the management of public and broadcasting spectrums which have traditionally been undercharged compared to their economic values. In this paper, we discuss the economic value valuation of the frequencies for the fisheries communications. The estimated value is the average value of the total equipment cost of the mobile communication services that their service coverage is nation-wide, and the value that adjusted the auction price for the LTE service frequencies in 2011 to the characteristics of fisheries communications.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.471-475
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• 2003

This paper proposes a sensor-fusion technique where the data sets for the previous moments are properly transformed and fused into the current data sets to enable accurate measurement, such as, distance to an obstacle and location of the service robot itself. In the conventional fusion schemes, the measurement is dependent on the current data sets. As the results, more of sensors are required to measure a certain physical parameter or to improve the accuracy of the measurement. However, in this approach, instead of adding more sensors to the system, the temporal sequence of the data sets are stored and utilized for the measurement improvement. Theoretical basis is illustrated by examples and the effectiveness is proved through the simulations. Finally, the new space and time sensor fusion (STSF) scheme is applied to the control of a mobile robot in an unstructured environment as well as structured environment.